$(function () {
    'use strict';

    QUnit.module('scrollspy plugin')

    QUnit.test('should be defined on jquery object', function (assert) {
        assert.expect(1)
        assert.ok($(document.body).scrollspy, 'scrollspy method is defined')
    })

    QUnit.module('scrollspy', {
        beforeEach: function () {
            // Run all tests in noConflict mode -- it's the only way to ensure that the plugin works in noConflict mode
            $.fn.bootstrapScrollspy = $.fn.scrollspy.noConflict()
        },
        afterEach: function () {
            $.fn.scrollspy = $.fn.bootstrapScrollspy
            delete $.fn.bootstrapScrollspy
        }
    })

    QUnit.test('should provide no conflict', function (assert) {
        assert.expect(1)
        assert.strictEqual($.fn.scrollspy, undefined, 'scrollspy was set back to undefined (org value)')
    })

    QUnit.test('should return jquery collection containing the element', function (assert) {
        assert.expect(2)
        var $el = $('<div/>')
        var $scrollspy = $el.bootstrapScrollspy()
        assert.ok($scrollspy instanceof $, 'returns jquery collection')
        assert.strictEqual($scrollspy[0], $el[0], 'collection contains element')
    })

    QUnit.test('should only switch "active" class on current target', function (assert) {
        assert.expect(1)
        var done = assert.async()

        var sectionHTML = '<div id="root" class="active">'
            + '<div class="topbar">'
            + '<div class="topbar-inner">'
            + '<div class="container" id="ss-target">'
            + '<ul class="nav">'
            + '<li><a href="#masthead">Overview</a></li>'
            + '<li><a href="#detail">Detail</a></li>'
            + '</ul>'
            + '</div>'
            + '</div>'
            + '</div>'
            + '<div id="scrollspy-example" style="height: 100px; overflow: auto;">'
            + '<div style="height: 200px;">'
            + '<h4 id="masthead">Overview</h4>'
            + '<p style="height: 200px">'
            + 'Ad leggings keytar, brunch id art party dolor labore.'
            + '</p>'
            + '</div>'
            + '<div style="height: 200px;">'
            + '<h4 id="detail">Detail</h4>'
            + '<p style="height: 200px">'
            + 'Veniam marfa mustache skateboard, adipisicing fugiat velit pitchfork beard.'
            + '</p>'
            + '</div>'
            + '</div>'
            + '</div>'
        var $section = $(sectionHTML).appendTo('#qunit-fixture')

        var $scrollspy = $section
            .show()
            .find('#scrollspy-example')
            .bootstrapScrollspy({target: '#ss-target'})

        $scrollspy.on('scroll.bs.scrollspy', function () {
            assert.ok($section.hasClass('active'), '"active" class still on root node')
            done()
        })

        $scrollspy.scrollTop(350)
    })

    QUnit.test('should correctly select middle navigation option when large offset is used', function (assert) {
        assert.expect(3)
        var done = assert.async()

        var sectionHTML = '<div id="header" style="height: 500px;"></div>'
            + '<nav id="navigation" class="navbar">'
            + '<ul class="nav navbar-nav">'
            + '<li class="active"><a id="one-link" href="#one">One</a></li>'
            + '<li><a id="two-link" href="#two">Two</a></li>'
            + '<li><a id="three-link" href="#three">Three</a></li>'
            + '</ul>'
            + '</nav>'
            + '<div id="content" style="height: 200px; overflow-y: auto;">'
            + '<div id="one" style="height: 500px;"></div>'
            + '<div id="two" style="height: 300px;"></div>'
            + '<div id="three" style="height: 10px;"></div>'
            + '</div>'
        var $section = $(sectionHTML).appendTo('#qunit-fixture')
        var $scrollspy = $section
            .show()
            .filter('#content')

        $scrollspy.bootstrapScrollspy({target: '#navigation', offset: $scrollspy.position().top})

        $scrollspy.on('scroll.bs.scrollspy', function () {
            assert.ok(!$section.find('#one-link').parent().hasClass('active'), '"active" class removed from first section')
            assert.ok($section.find('#two-link').parent().hasClass('active'), '"active" class on middle section')
            assert.ok(!$section.find('#three-link').parent().hasClass('active'), '"active" class not on last section')
            done()
        })

        $scrollspy.scrollTop(550)
    })

    QUnit.test('should add the active class to the correct element', function (assert) {
        assert.expect(2)
        var navbarHtml =
            '<nav class="navbar">'
            + '<ul class="nav">'
            + '<li id="li-1"><a href="#div-1">div 1</a></li>'
            + '<li id="li-2"><a href="#div-2">div 2</a></li>'
            + '</ul>'
            + '</nav>'
        var contentHtml =
            '<div class="content" style="overflow: auto; height: 50px">'
            + '<div id="div-1" style="height: 100px; padding: 0; margin: 0">div 1</div>'
            + '<div id="div-2" style="height: 200px; padding: 0; margin: 0">div 2</div>'
            + '</div>'

        $(navbarHtml).appendTo('#qunit-fixture')
        var $content = $(contentHtml)
            .appendTo('#qunit-fixture')
            .bootstrapScrollspy({offset: 0, target: '.navbar'})

        var done = assert.async()
        var testElementIsActiveAfterScroll = function (element, target) {
            var deferred = $.Deferred()
            var scrollHeight = Math.ceil($content.scrollTop() + $(target).position().top)
            $content.one('scroll', function () {
                assert.ok($(element).hasClass('active'), 'target:' + target + ', element' + element)
                deferred.resolve()
            })
            $content.scrollTop(scrollHeight)
            return deferred.promise()
        }

        $.when(testElementIsActiveAfterScroll('#li-1', '#div-1'))
            .then(function () {
                return testElementIsActiveAfterScroll('#li-2', '#div-2')
            })
            .then(function () {
                done()
            })
    })

    QUnit.test('should add the active class correctly when there are nested elements at 0 scroll offset', function (assert) {
        assert.expect(6)
        var times = 0
        var done = assert.async()
        var navbarHtml = '<nav id="navigation" class="navbar">'
            + '<ul class="nav">'
            + '<li id="li-1"><a href="#div-1">div 1</a>'
            + '<ul>'
            + '<li id="li-2"><a href="#div-2">div 2</a></li>'
            + '</ul>'
            + '</li>'
            + '</ul>'
            + '</nav>'

        var contentHtml = '<div class="content" style="position: absolute; top: 0px; overflow: auto; height: 50px">'
            + '<div id="div-1" style="padding: 0; margin: 0">'
            + '<div id="div-2" style="height: 200px; padding: 0; margin: 0">div 2</div>'
            + '</div>'
            + '</div>'

        $(navbarHtml).appendTo('#qunit-fixture')

        var $content = $(contentHtml)
            .appendTo('#qunit-fixture')
            .bootstrapScrollspy({offset: 0, target: '#navigation'})

        !function testActiveElements() {
            if (++times > 3) return done()

            $content.one('scroll', function () {
                assert.ok($('#li-1').hasClass('active'), 'nav item for outer element has "active" class')
                assert.ok($('#li-2').hasClass('active'), 'nav item for inner element has "active" class')
                testActiveElements()
            })

            $content.scrollTop($content.scrollTop() + 10)
        }()
    })

    QUnit.test('should clear selection if above the first section', function (assert) {
        assert.expect(3)
        var done = assert.async()

        var sectionHTML = '<div id="header" style="height: 500px;"></div>'
            + '<nav id="navigation" class="navbar">'
            + '<ul class="nav navbar-nav">'
            + '<li class="active"><a id="one-link" href="#one">One</a></li>'
            + '<li><a id="two-link" href="#two">Two</a></li>'
            + '<li><a id="three-link" href="#three">Three</a></li>'
            + '</ul>'
            + '</nav>'
        $(sectionHTML).appendTo('#qunit-fixture')

        var scrollspyHTML = '<div id="content" style="height: 200px; overflow-y: auto;">'
            + '<div id="spacer" style="height: 100px;"/>'
            + '<div id="one" style="height: 100px;"/>'
            + '<div id="two" style="height: 100px;"/>'
            + '<div id="three" style="height: 100px;"/>'
            + '<div id="spacer" style="height: 100px;"/>'
            + '</div>'
        var $scrollspy = $(scrollspyHTML).appendTo('#qunit-fixture')

        $scrollspy
            .bootstrapScrollspy({
                target: '#navigation',
                offset: $scrollspy.position().top
            })
            .one('scroll.bs.scrollspy', function () {
                assert.strictEqual($('.active').length, 1, '"active" class on only one element present')
                assert.strictEqual($('.active').has('#two-link').length, 1, '"active" class on second section')

                $scrollspy
                    .one('scroll.bs.scrollspy', function () {
                        assert.strictEqual($('.active').length, 0, 'selection cleared')
                        done()
                    })
                    .scrollTop(0)
            })
            .scrollTop(201)
    })

    QUnit.test('should correctly select navigation element on backward scrolling when each target section height is 100%', function (assert) {
        assert.expect(5)
        var navbarHtml =
            '<nav class="navbar">'
            + '<ul class="nav">'
            + '<li id="li-100-1"><a href="#div-100-1">div 1</a></li>'
            + '<li id="li-100-2"><a href="#div-100-2">div 2</a></li>'
            + '<li id="li-100-3"><a href="#div-100-3">div 3</a></li>'
            + '<li id="li-100-4"><a href="#div-100-4">div 4</a></li>'
            + '<li id="li-100-5"><a href="#div-100-5">div 5</a></li>'
            + '</ul>'
            + '</nav>'
        var contentHtml =
            '<div class="content" style="position: relative; overflow: auto; height: 100px">'
            + '<div id="div-100-1" style="position: relative; height: 100%; padding: 0; margin: 0">div 1</div>'
            + '<div id="div-100-2" style="position: relative; height: 100%; padding: 0; margin: 0">div 2</div>'
            + '<div id="div-100-3" style="position: relative; height: 100%; padding: 0; margin: 0">div 3</div>'
            + '<div id="div-100-4" style="position: relative; height: 100%; padding: 0; margin: 0">div 4</div>'
            + '<div id="div-100-5" style="position: relative; height: 100%; padding: 0; margin: 0">div 5</div>'
            + '</div>'

        $(navbarHtml).appendTo('#qunit-fixture')
        var $content = $(contentHtml)
            .appendTo('#qunit-fixture')
            .bootstrapScrollspy({offset: 0, target: '.navbar'})

        var testElementIsActiveAfterScroll = function (element, target) {
            var deferred = $.Deferred()
            var scrollHeight = Math.ceil($content.scrollTop() + $(target).position().top)
            $content.one('scroll', function () {
                assert.ok($(element).hasClass('active'), 'target:' + target + ', element: ' + element)
                deferred.resolve()
            })
            $content.scrollTop(scrollHeight)
            return deferred.promise()
        }

        var done = assert.async()
        $.when(testElementIsActiveAfterScroll('#li-100-5', '#div-100-5'))
            .then(function () {
                return testElementIsActiveAfterScroll('#li-100-4', '#div-100-4')
            })
            .then(function () {
                return testElementIsActiveAfterScroll('#li-100-3', '#div-100-3')
            })
            .then(function () {
                return testElementIsActiveAfterScroll('#li-100-2', '#div-100-2')
            })
            .then(function () {
                return testElementIsActiveAfterScroll('#li-100-1', '#div-100-1')
            })
            .then(function () {
                done()
            })
    })

})
